1. Field of the Invention
The present invention relates to a pure water tank for a fuel cell system.
2. Description of the Related Art
A fuel cell system uses pure water to humidify fuel gas and oxidizing gas supplied to a fuel cell stack. Pure water in a pure water tank for the fuel cell system freezes in a case where a vehicle equipped with the fuel cell system is parked for a long time in cold climates.
To improve the starting ability of the fuel cell system, the pure water in the pure water tank must be thawed as quickly as possible. To thaw the pure water, one related art divides the pure water tank into a large main tank and a small supplementary tank and heats the main tank with warmed coolant and the supplementary tank with a heater.